The present invention relates to an air brake valve used in an anti-lock brake system for commercial vehicles. In particular, this invention relates to electro-pneumatic air brake valves, also known as modulators. A modulator is capable of applying and releasing the air pressure at the wheel end to mitigate wheel lock up during an anti-lock braking event.
Commercial vehicles equipped with air brakes must meet the release timing requirements of Federal Motor Vehicle Safety Standard (FMVSS) 121 for Air Brake Systems. The release timing requirements relate to how quickly the brakes release after the brake pedal is allowed to return to its normal position. A modulator must be able to quickly exhaust the air pressure after an anti-lock braking event in order to meet the timing requirements.